侏罗纪是世界重要的成煤期，同时也是中生代裸子植物繁盛的时期。甘肃窑街是西北地区侏罗系窑街组的标准剖面地点，该含煤盆地植物化石丰富，且保存完好。本项目拟以窑街盆地已发现的丰富的银杏类、松柏类、苏铁类裸子植物化石为研究对象，以形态学描述及表皮微细构造特征研究为基础，对窑街侏罗纪裸子植物进行系统分类学研究，探究裸子植物的系统演化；运用数量分析法对窑街重要裸子植物进行数量分类，对其中分类位置较为确定的属种建立分种检索表及Bayes判别模型，为裸子植物的分类鉴定提供新方法。分析化石植物表皮气孔密度和气孔指数推测古大气CO2浓度，对早侏罗世至晚侏罗世古大气 CO2 浓度进行重新估算，并与前人重建的中国西北地区中生代古大气 CO2 做对比。结合植物多样性分析和与现生类群的比较，依据裸子植物角质层微细构造及古大气CO2变化趋势，探究侏罗纪不同时期的古气候演变规律和古环境变迁历史。

Jurassic is an important coal-forming period in the world, and also a flourishing period of Mesozoic Gymnosperms. Yaojie Basin is the standard section of the Jurassic Yaojie Formation in Northwest China. The coal-bearing basin is rich in plant fossils and well preserved. In this project, the abundant Gymnosperms fossil of Ginkgosida，Coniferopsida and Cycadopsida discovered in Yaojie Basin are taken as the research objects, and the systematic taxonomy of Jurassic Gymnosperms in Yaojie Basin will be studied on the basis of morphological description and the study of epidermal microstructural characteristics, so as to explore the phylogenetic evolution of Gymnosperms. We will use the quantitative analysis method to classify the important Gymnosperms in Yaojie, and establish an identification key and a Bayes discriminant model for the genus with a definite taxonomic positions, which will provide a new method for the classification and identification of Gymnosperms. Based on the analysis of stomatal density and stomatal index of fossil plants epidermis, the paleoatmospheric CO2 concentration from Early Jurassic to Late Jurassic will be recalculated, and compare with the Mesozoic paleoatmospheric CO2 reconstructed by predecessors in Northwest China. Based on the analysis of plant diversity and the comparison with living groups, the paleoclimatic evolution rules and paleoenvironmental change history in different periods of Jurassic will be explored according to the microstructure of the stratum corneum of Gymnosperms and the change trend of paleoatmospheric CO2.